Well, it's not clear to me from reading your post that you did the recovery BIOS correctly. Did you remove the jumper completely when you attempted the recovery BIOS update? After the BIOS update, you replace the jumper. Check the tech documents to ensure you are doing it correctly.

Remove the CMOS battery for a few hours, check the battery voltage, replace battery if suspect, attempt another recovery BIOS update with minimal hardware to see if you can get a board that will boot with the latest BIOS.

Try another download of the BIOS update. I've had what appears to be corrupted downloads before. I've been successful with a second download where the first download failed. If you're up for it, try another download of the recovery BIOS update and do a full reformat of the disk or usb that you intend to use for the update before you copy the BIOS update to that media. Put the board in the simplest configuration possible, by removing all unnecessary hardware from the system. If that fails, then you likely have a damaged board.

YES; i've also dad a bad download before (DH55TC, I believe) IIRC It was way too small, so I noticed after the third attempt, Since then I always download all 3 versions of the bios (bio, zip, exe) and extract and compare them.

This time, the bio and bio in the zip have the same size, I tried both.

Eevn then, the board never even tries to access eithet the flash drive or the disk.

BTW, have you also noticed that the 5V Standby led never goes out completely as long as you have a monitor connected?

The sum of all the 'small things' in this board makes me kinda nervous. It looks like an unfinished engeneering sample to me.

@rseiler

I think I read something similar before, was that also you? Anyway, I totally agree.

However in this specific case, I was really waiting for a new BIOS, because, As I said in my first post, I already was having a number of issues, which I am sure needed a BIOS fix. Even though INtel support never acknowledged them. Now sure enoufgh, the release notes of the 040 BIOS conatins almost all those issues, so I was really in need to apply that.

So now: black screen, no beeps !!

INterestingly lights are somewaht on 5V stby power led, no beeps even when no memory.

BTW, I wasn'T overclocking anything before I applied the BIOS. Although I do have a 2600K proc in it, but just because the 'normal' ones weren't available at the time I bought them, and they would have been the price anyway.

I don't have a DZ68DB, but I do have the DX58SO and the 5 V standby voltage LED will remain lit unless I switch off the power supply with the switch on the power supply or unplug the power supply. Even then, the LED doesn't go out immediately; it will remain lit for about another ten seconds or more. I've never had to disconnect my monitors to remove standby voltage from the motherboard. My monitors are connected to an Nvidia graphics card and the power doesn't get to the board from the monitors.

Are you sure your monitor is providing standby power to the Intel board? Will your board have standby power connected to a monitor and the system power supply unit unplugged? As I indicated, I'm not familiar with your board, but I would think it's got a problem if you've got standby power through a monitor alone.

If you remove or install memory modules with standby power present, you could fry something.

The normal procedure of getting the system powerless is to switch off, then unplug.

The stby Power led will stay on as you said for a few seconds, but you can press the power switch to drain it immediately.

Even then you never know how many other capacitors have somehing left.

Anyway, if you connect a monitor to the onboard gfx (HDMI other DVI, tried both, with different different monitors), then I notice that the stby LED never goes out completely, it still glows a bit (dimly, not full) until I also disconnect the monitor. This effect has been reported here elswhere by someone else too.

Of course monitor and PC are on the same power grid.

Whatever, I'm not sure this has something to do with the failed BIOS update, but it just adds up to all the small things.

The Intel technical documents don't caution about disconnecting monitors or anything else besides the power supply unit before changing memory modules. Your board has integrated graphics support which is different from my board. You may have a defective or damaged board.

I RMA'ed the first one because I also thought I had killed the board with a BIOS updated AND I saw the standby power stay on even with power unplugged from the power supply.

The second board also had the same issues.

The BIOS upgrades change the video settings that cause the display 'auto detection' to not work after the BIOS upgrade has been completed. This makes it look like the BIOS upgrade has killed the motherboard. In your particular case I think it has indeed killed the motherboard because changing the BIOS configuration jumper to configure should allow you to change the BIOS settings to force the video signal to the correct port.

The monitor is powering the motherboard though the +5V supply on the video cable. The Intel representative told me that this was on purpose to "alert the user that there is still power applied to the motherboard". While technically this is true, I would hope that the motherboard design would prevent this +5V signal from affecting components that you might swap out with the power supply unplugged. I don't know but I make sure to power off my monitor as well when swapping out any component.

These are a couple of the issues I have been facing with on the board that I have been living with. I'm not extremely happy but these particular issues can be worked around.

I haven't had any USB 3 issues -- but I also don't use USB3 very often.

I almost forgot -- I also had to enable another BIOS setting (sorry I'm not at this particular computer right now to look it up) to delay switching off the power supply (by I think 4 seconds) or the system would not correctly flash the BIOS. This is another setting that gets wiped out when flashing the BIOS.

I'm really scared about applying BIOS 0040 to my system but would like to because every couple months the system freezes with a checkerboard pattern on the display. I don't have anything in the system except for an Intel SSD.

The 5 Volt standby power issue appears to be a design flaw in my opinion. Intel should post a warning in the tech documents to ensure all devices with power attached to the system are unplugged to ensure no standby power exists on the board when changing memory modules.

I'm having the same problem. brand new dz68db last i5 cpu,16GB ram. Board only works with 12GB RAM regardless of speed settings. It came with bios 0014. I spent 3 days trying to get it to 0040. 2 days ago I got it to 0032. Then tried to get it to 0040. Now the board will not reboot. I've tried every way to get it to recover the bios. No luck. Left the battery out for 24 hours. No luck in recovery. I followed the jumper process exactly. Also not sure why the box says 32GB ram when it only takes 16GB max. I"m not sure what to do next. I'm losing money playing with this. No response from Intel on this yet? How do I get an RMA? Should I get another brand? This is my first Intel board. Not a pleasant experience so far.